Our modern world (newpapers, celebrity magazines, self-help books, films, television shows - both fiction and nonfiction) tells us that the purpose of marriage is to live happily ever after. Marriage should be about each spouse's satisfaction, fulfillment, and contentment. A good marriage itself is thought to confer these things. The underlying assumption here is that either the efforts of my husband are what make me happy or his lack of effort makes me unhappy. And if he's not making me happy, then the marriage isn't fulfilling its purpose, and therefore is somehow invalid or disposable. However, Jane Austen and Shakespeare shared a different view.
At the beginning of Pride and Prejudice, both Darcy and Elizabeth have some growing up to do. Even though Darcy is smitten by Eliza's 'fine eyes', after Elizabeth's initial interest in Darcy is quashed by his arrogance, she never really expresses a strong physical attraction for him, but is eventually attracted by his character and the growth she sees there. I read once that, without Darcy, Elizabeth would have ended up just like her father, distant and disdainful; without Elizabeth, Darcy would have ended up just like Lady Catherine de Bourgh, proud and unyielding. In other words, Elizabeth and Darcy are right for one another because they influence each other to be better people.
If we compare Elizabeth and Darcy's relationship with the relationships of the other married couples in the book, we see how important this is to Jane Austen. Mr. Bennet doesn't even try to make Mrs. Bennet a better person, but lets her go on in her foolish ways. He doesn't seem to want to influence anyone for the better, but is content to sit back and merely laugh at the folly of others, including that of his wife and younger daughters. Charlotte and Mr. Collins also have no gentling effect on each another, content merely to exist in the same house, spending as much time apart as possible. Lydia and Wickham not only don't try to affect change in one another, but actually reinforce each other's folly and sin. The author's attitude toward all these couples is clear - they are not examples to be followed.
In The Taming of the Shrew, Petruchio doesn't love Katharina when he seeks permission from Baptista to marry her. He really wants her inheritance. He wants a wife, and because she's rich and he has no competition, she'll do. Katharina starts out hard, selfish, violent, lazy, ungrateful, unloving - in other words, a shrew. However, he, even with his less-than-romantic motives, is the right husband for her because he teaches her gentleness, duty, responsibility, gratitude, grace, and love.
Looking at the other couples (because foils can tell us so much about authorial intent), even though Lucentio and Bianca are head over heals in love, she has all the makings of a shrew as she rebels against her husband in the final scene; she may be gentle and beautiful on the outside, but it seems her heart doesn't follow suit. And Hortensio and the Widow, whom I suspect Shakespeare married to one another merely to give us another cautionary example as their courtship happens off-stage and out of sight, are in no better position than Lucentio and Bianca. Lucentio and Hortensio are losers in the wager of marriage because they have no influence over their wives.
Both Jane Austen and Shakespeare understood that the purpose of marriage is not our happiness, but our holiness
If the purpose of marriage isn't happiness, but holiness, unhappiness doesn't invalidate a marriage, or justify walking out when the going gets tough or boring and mundane. A husband isn't responsible for his wife's happiness. Rather, we are each responsible to influence our individual husbands toward godliness (not as a form of manipulation in an effort to make our lives easier, but out of love and even self-sacrifice, doing what is best for another) also eagerly expecting our husbands to influence us in the same direction.
Now, I'm not saying that marriage should be primarily a chore and a trial that we merely survive. However, we must realize that happiness in marriage is a result of focusing on the true purpose of marriage. As we strive to be more Christlike, iron sharpening iron, we will experience more joy. (This is just one more example of ethereal ideas having tangible consequences.)
Among all these couples in both works, whom do you think will end up being the happiest? My money is on Darcy and Elizabeth, and Petruchio and Katharina. And if they lived today, I bet they'd celebrate at least 50 years of marriage one day because they'd get through the tough times, even in a culture of easy divorce.